单项选择题
I was absorbed ______ what I was reading and didn"t hear the knock.
单项选择题 The sign reads "In case of ______ fire, break the glass and push ______ red button. "
单项选择题 Peter said that he wouldn"t mind ______ the windows.
单项选择题 As soon as the supplies arrive, they will be ______ to the starving people.
